Joseph Naso, the alleged serial killer defending himself against charges he murdered four women, told a Marin County jury Monday that the prosecution's case amounts to "character assassination."

Naso, speaking on the first day of his trial, said the prosecution's circumstantial evidence is weak, its DNA evidence is inconclusive and his writings about violent sex with "broads" are being misconstrued.

"I'm not the monster that killed these women," said Naso, 79, a retired photographer. "I didn't do that. If I thought I was guilty of these crimes, I would have had to hire two or three of the best attorneys in the Bay Area. I'm very comfortable representing myself."

Naso's remarks followed a detailed presentation by Deputy District Attorney Rosemary Slote, who showed the jury crime scene photos of the four naked victims, some of whose bodies were partially decomposed. Slote described how a vast record of evidence over the past 50 years points to Naso as a "serial rapist and murderer."

Slote also unveiled new evidence — just confirmed in recent weeks, too late for charges in this trial — she says implicates Naso in the death of a Bob Dylan groupie who vanished in 1992.

The four victims for whom Naso is charged were known prostitutes who worked near his former residences in Piedmont and Yuba City. All four were dumped along rural roads.

The victims were Roxene Roggasch, 18, who was found off Sir Francis Drake Boulevard near Fairfax in 1977; Carmen Colon, 22, found near Port Costa in 1978; Pamela Parsons, 38, found in Yuba County in 1993; and Tracy Tafoya, 31, found in Yuba County in 1994.

The homicide cases languished until 2010, when a routine probation check at Naso's home in Reno revealed an extensive collection of photographs of dead or unconscious women in various states of undress, incriminating writings and sadistic magazines, investigators said.

The search also turned up what authorities describe as a "list of 10" — a roster, in Naso's handwriting, of 10 unnamed "girls" with geographic locations. Prosecutors allege the list refers to 10 women Naso killed and the areas where he dumped their bodies.

Four of the women on the list correlate to Roggasch, Colon, Parsons and Tafoya, prosecutors allege. Investigators said semen on Roggasch's pantyhose matched Naso's DNA profile, and that Roggasch was strangled with panty hose that contained the DNA of Naso's wife.

Naso also had numerous images of Parsons in his photography collection, and he admitted he dated Tafoya.

In court Monday, prosecutor Slote said investigators recently identified a fifth alleged victim on the list, even though it was too late to file a murder charge without delaying the trial. The woman's name is Sara Dylan.

Dylan's passport was among the items found in a safe deposit box that Naso kept in Reno. Investigators learned that Sara Dylan, who was adopted as a baby in Texas, grew up with the name Renee Shapiro, but she was such a fan of the singer Bob Dylan that she legally changed her name to that of his former wife.

Slote said the woman followed Bob Dylan's tour around the world and, in 1992, traveled to Northern California to see one of his shows. Dylan, who was known to hitchhike to concerts, never made it to the show and was reported missing.

After the Naso case broke, the FBI eventually tracked down the biological mother of Dylan, who had been adopted by the Shapiro family as a baby. Slote said the mother's DNA was recently matched to a skull found near the Nevada County border some years ago.

Authorities have not announced identities for the remaining five women on the list of 10, but the investigation is ongoing.

Also Monday, the prosecution showed jurors excerpts of what it describes as Naso's "rape journal," a diary that appears to document the rapes of various women and girls, some in the Rochester, N.Y., area as far back as the 1950s and '60s.

In one 1958 entry — listed as entry No. 40 — Naso describes offering a ride to a "gorgeous chick" after he had stalked her to the point of knowing her work schedule. Then he describes taking her to a cemetery and raping her.

"It was hard work trying to hold her down and pull off her underwear at the same time," he wrote.

Then he drove the victim home and waited while she rushed inside to her mother, thinking she wanted to introduce Naso to her family. Instead, the mother came out and wrote down Naso's license plate number, and he was eventually convicted of assault to commit rape, Slote said.

Naso, in his statement to the jury Monday, acknowledged the conviction but complained the prosecution is trying to extrapolate its whole "serial killer" theory from one old crime.

He also said the language in his journals does not mean he is a rapist.

"That's the way I talk," he said. "'I picked up a nice broad,' and 'I picked up another broad and raped her,'" he said. "It's not forcible rape."

Later, he offered the jurors "some advice."

"Don't keep records," he said.

The trial continues Tuesday before Judge Andrew Sweet. It is expected to last about five months.

The jury consists of six men and six women ranging from 19 to 79 years old, including a lawyer and a court clerk, an attorney said. The jury also has nine alternates, an unusually high number, who will listen to evidence in case other jurors are unable to complete the trial.

Although Naso insisted on being his own lawyer, he has limited assistance from an advisory counsel, Deputy Public Defender Pedro Oliveros.

It remains to be seen whether Naso himself will testify on his own behalf, thus subjecting himself to cross-examination by trial prosecutors.